Female contraceptives. Illustration of female contraceptives and a woman's reproductive system. The contraceptives are: an injectable hormone (vial, far left), levonorgestrel-releasing implants (tubes, upper right), an intrauterine contraceptive device (IUD, bottom right), a copper IUD (at centre in the uterus) and a cap or diaphragm (top right). Injectable hormones are injected into muscle, while the hormone-releasing capsules are implanted under the skin of the upper arm. Both methods interfere with egg release from the ovaries (one seen sectioned at centre right). Caps are put on the cervix (the base of the uterus, lower left) to prevent sperm from entering the uterus. IUDs are thought to stop the fertilised egg from implanting in the uterus.